This invention relates to an automatic grabbing device for handling articles. More particularly, this invention relates to an automatic grabbing device which is mounted on the end of a control arm and which comprises a plate equipped with a pair of claws. The claws are mounted facing one another on the plate; with one claw being slidably mounted and the other claw being pivotably mounted. The invention also relates to a robot equipped with said grabbing device.
The present invention, although not being limited thereto in its utility, relates more particularly to a grabbing means for handling refractory bricks for producing an inner refractory lining of a metallurigical vessel, such as a convertor; and the present invention will be described in more detail with reference to this preferred application.
It is known that the refractory lining of a convertor has to be repaired very frequently, i.e., at least once every three weeks. Until now, this very laborious and tiring job has always been carried out manually in spite of several attempts at automation. It will be appreciated that the use of robots to carry out this brick laying work can be considered only if it permits the preclusion of practically all manual involvement; and if the work rate is at least as fast as in manual laying. However, not only are the movements necessary for picking up the bricks from the pallets and placing them in the required position already complicated per se; but, in addition, there are usually two different types of bricks, thus making automation even more complicated. In fact, it will be appreciated that, in order for bricks to be laid in a circle, the bricks must have a trapezoidal shape, that is, the extensions of their longitudinal sides must converge towards the central axis of the convertor. Moreover, because it is impossible to make bricks to measure, there is usually a stack or two or more standard types of bricks of differing conicity; and wherever the bricks laid diverge too much from the shape of the wall of the convertor, the type of brick is changed. Because of all these complications, it has not yet been possible or practical to carry out brick laying operations by means of a robot.